Hired to care for a reclusive elderly author (Paula Prentiss), a best-selling author of ghost stories, a live-in nurse, Lily (Ruth Wilson), comes to believe that the pair is not entirely alone and the house holds an horrific ghost story of its own.

Season 3 opens with Noah (Dominic West), Alison (Ruth Wilson), Cole (Joshua Jackson), Helen (Maura Tierney) and their families trying to move on with their lives. But the past keeps coming back to haunt them, and the trauma of what they've been through cannot soon be forgotten.